1. Field of the Invention
The present invention relates to a printing unit for a web-fed rotary printing machine having a plurality of printing unit cylinders that each have their own drive motor. A carriage guide means allows the cylinders to be set in relation to one another.
2. Description of the Related Art
German reference no. 195 34 651.3 discloses a printing unit having two frame walls running parallel to ends of the printing unit cylinders. The printing unit cylinders can be fitted with different diameter sleeves for altering the length of the printed image. A carriage is provided on the frame walls on both sides of the printing unit cylinder for mounting the ends of a printing unit cylinder onto the printing unit. The carriages are adjustable by means of pressure operated working cylinders. This design is relatively complicated.
The object of the present invention is to provide a generic printing unit having a simple, cost effective structure and being relatively narrow in width.
A further object of the present invention is to avoid oscillations from one printing unit cylinder from being transmitted to other printing unit cylinders via the means for setting the carriages.
Another object of the present invention is to provide long carriage guide systems to accommodate wide carriages.
The present invention is a printing unit for a web fed rotary printing machine comprising a plurality of cylinders; a corresponding drive motor for each of the cylinders; a machine frame which includes at least one load bearing wall, including two mutually facing wall surfaces perpendicular to a plane through end faces of the cylinders, wherein the at least one load bearing wall is arranged laterally beside an end of the cylinders; a guide means including a plurality of guide elements arranged on the at least one load bearing wall; a plurality of carriages, wherein each carriage is operably attached to at least one of the plurality of guide elements; at least one driven screw spindle mounted on the machine frame; and a permanently threaded nut engaged by an associated driven screw spindle for setting the location of the carriages.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of the disclosure. For a better understanding of the invention, its operating advantages, and specific objects attained by its use, reference should be had to the drawing and descriptive matter in which there are illustrated and described preferred embodiments of the invention.